A vertical charge control semiconductor device is disclosed in the above-referenced patent applications wherein a trench extends through a first or base layer of the device and a substantial distance into the second or drift layer of the device. More particularly, these applications specify that the vertical charge control device exhibit an aspect ratio in the second or drift layer (which is defined as the ratio of the depth of the trench to the width of the pedestal defined by the trench) which is greater than or equal to 0.5. These vertical devices intended to have a breakdown voltage in excess of 400 volts require the establishment of a substantially vertical trench having a depth greater than or equal to 10 microns. Various process difficulties have been discovered in the course of fabricating trenches of these depths and it has not always been possible to accurately provide a trench of desired depth. Thus it is not possible to use standard vertical charge control techniques to achieve a device which exhibits a breakdown voltage in excess of 400 volts. Further, it has not been possible to provide vertical charge control devices which exhibit consistent performance within a desired high voltage range.
Accordingly, it is desirable to provide a lateral charge control semiconductor device which does not employ a deep trench and thus is not susceptible to the difficulties associated with providing a deep trench.